effected by running the water very slowly through the condenser
so that the upper part remains warm. Theiodotoluene solidifies
in the receiver. It has a yellow tint, which may be removed by
recrystallisation from spirit. Yield, 45—50 grams.
CH3.C(5H1N,,SO,H + KI = CH,.C«H4I + N2+ KHSO4.
Properties.—-Colourless plates ; m. p. 35° ; b. p. 211—212°.
1. Tolyliodochloride.—Dissolve TO grams iodotoluene in
five times its weight of chloroform, cool in ice, and pass in dry
chlorine until saturated. If a chlorine cylinder is not available,
the chlorine is conveniently made by dropping concentrated
hydrochloric acid from a tap-funnel on to powdered potassium
bichromate or permanganate in a round flask, heated on the
water-bath. The chlorine is dried through concentrated
sulphuric acid. When chlorine is no longer absorbed, the
yellow needle-shaped crystals of the ioclochloride are filtered,
washed with a little chloroform, and dried on a porous plate.
CH3.C0H4I + C13= CH3.CaH4ICl2.
2. lodosotoluene.—Dissolve 2-5 grams caustic soda in 20
c.c. water, and grind with 5 grams of iodochloricle in a mortar.
Leave overnight and then filter and wash with water. The
colourless crystals of the iodoso-compound are dried on a porous
CIl;,C(;H.llCl.H-2Na()H = CH;t.CtiHJO + 2NaCl + H2O.
See Appendix, p. 285.
Sandmeyer, />Vr., 1884, 17, 2653.
20 grins, /-toluidine.
45 c.c. cone, hydrochloric acid (in 150 c.c. water).
16 grins, sodium nitrite (in 40 c.c. water).
50 „ copper sulphate (in 200 c.c. water).
55 „ potassium cyanide (in 100 c.c. water).
The copper sulphate is dissolved in 200. c.c. water on the
water-bath in a round flask (2 litres). Pure potassium cyanide